short stature

short stature
Growth disturbances manifest as abnormal absolute height or growth velocity.
?Short stature is defined as height that is two standard deviations below the mean height for age and sex (less than the 3rd percentile) or more than two standard deviations below the midparental height.
?Growth velocity disorder is defined as an abnormally slow growth rate, which may manifest as height deceleration across two major percentile lines on the growth chart
physiology of growth
three phases
?after birth: infancy, childhood and pubertal growth
?.1st year 25cm/year
?2-3 year 7.5-13cm/year
?7cm/year at 3-4 year s and
?6cm/year at 5-6 years. It then remains at 4-6cm/year
?until puberty occurs when their growth will slow to about 4 cm/year
?Girls have their peak height velocity at early puberty, 9cm/year .
?Boys reach their peak height velocity during midpuberty , with growth rate 10cm/year
?In male skeletal growth till 17years while in female till age of 14 years
?.
Types of short ststure
?A-Genetic short stature/Familial short stature
?the most common type
? a condition characterized by
?1- height below the third percentile for age,
?2- normal annual growth rate
?3- normal bone age,
?4- family history of short stature,
?5- expected adult height below the third percentile,
?6- normal onset of puberty,
?7- and normal result to findings on physical examination
?8- no endocrine abnormalities.,
?.Late bloomer))B-Constitutional growth delay
?1- No signs or symptoms of systemic disease
?2- Bone age delayed up to 2 to 4 years but consistent with height age (age at which individual’s height would plot on the 50th percentile)
?3- Period of poorest growth often occurring between the ages of 18 and 30 months, with steady linear growth thereafter (i.e., normal rate of growth for bone age)
?4- IGF-1 levels tend to be low for chronological age but within the normal range for bone age.
?5- GH responses to provocative testing tend to be lower than in children with a more typical timing of puberty.
?6- Parental or sibling history of delayed physical development
?7-Height prediction consistent with family characteristics
?8-delayed puberty with normal eventual height.
How is constitutional delay managed?
?the child is seen once every 3 to 6 months for accurate height measurements
?and determination of growth velocity. A bone age test may be done yearly to assess the
?progression of bony maturation.
?In children who are of mid- to late
?pubertal ages (girls >13 years; boys >14 years) but showing minimal or no `signs of puberty,
?selective use may be made of estrogen or testosterone supplementation to initiate puberty,
?additional assessment may be indicated
C-Short stature following small for gestational age (SGA)
It is result from fetal, placental, maternal
Could be symmetrical (early)
Or asymmetrical (late)
D-Dysmorphic syndromes
1- turner syndrome Always think of Turner’s in Girls

2- Noonan Syndrome,
3-RussellSilver,
4- Williams Syndrome
5- Down’s .Prader-Willi syndrome,

E-Endocrine disorders
?1-Growth hormone insufficiency is the most type , congenital, acquired secondary to CNS tumors, radiotherapy for malignancy, meningitis, histiocytosis, and trauma. head injury or even
?transient due to psychosocial deprivation) ) common
?2- severe GH presented with micropenis, hypoglycemia, less than 3year
?3- Hypothyroidism
?4-Cushing s Syndrome is another cause of short stature.
?The patient is usually obese and short
?Others causes
?1-skeletal dysplasia(achondrplasia) , (Mucopolysaccaridosis).
?2-celaic disease , IBD
?3- CHD
?4- Psychological deprivation
?SLE) ) 5- any chronic illness type
. Causes of short stature
?Genetic short stature
?Constitutional growth delay
?Combined genetic short stature and constitutional growth delay
?Short stature following small for gestational age
?Dysmorphic syndromes
?Endocrine disorders
?Skeletal dysplasia
?Chronic diseases
?Psychosocial deprivationA
. Assessment of short stature
? Accurate serial height measurements documented over time on a growth chart are key in the evaluation of children and serve as the foundation for the diagnosis of growth abnormalities.
?Height, weight, height velocity
?Height of parents
?Birth weight, gestation
?History of short stature, past medical history
?Family history of puberty, consanguinity, social history, school
?performance
?Systemic inquiry
?Examination of dysmorphic features
?Systemic examination
?Pubertal development staging
?Blood test if necessary (CBC, TSH, RFT, LFT)
?Radiological examination if necessary (bone age)
?Endocrine assessment (if indicated)
Isolated GH defeciency DX of
? A strong clinical suspicion is important in establishing the diagnosis because laboratory measures of GH sufficiency lack specificity,
? Random growth hormone levels are of little value because they are generally low in the daytime, even in children of average height.
? IGF-1 (or somatomedin C) mediates the anabolic effects of growth hormone, and levels correlate well with growth hormone status. However,IGF-1 can also be low in non endocrine conditions (e.g., malnutrition, liver disease), and the assays are somewhat inconsistent from laboratory to laboratory.
?IGFBP-3, which is the major binding protein for IGF-1 in serum, is also regulated by growth hormone. IGFBP-3 levels generally indicate growth hormone status and are less affected by nutritional factors than IGF-1.
?.
Many endocrinologists now use IGF-1 and IGFBP-3 as their initial screening tests for growth hormone deficiency, IGF-1 and IGF-BP3 levels should be matched to normal values for skeletal age rather than chronological age. Values in the upper part of the normal range for age effectively exclude GH deficiency.



Definitive diagnosis of GH deficiency traditionally requires demonstration of absent or low levels of GH in response to stimulation. A variety of provocative tests have been devised that rapidly increase the level of GH in normal children. These include administration of insulin, arginine, clonidine, or glucagon. In chronic GH deficiency, the demonstration of poor linear growth, delayed skeletal age, and peak levels of GH (<10 ng/mL) in each of 2 provocative tests, are compatible with GH deficiency

Treatment if isolated GH D
?The recommended dose of hGH is 0.18–0.3 mg/kg/wk during childhood. Higher doses have been used during puberty. Recombinant GH is administered subcutaneously in 6 or 7 divided doses AT night. Maximal response to GH occurs in the 1st year of treatment
?If growth rate drops below the 25th percentile, compliance should be evaluated before dose is increased
? the Criteria for stopping treatment include a decision by the patient that he or she is tall enough, a growth rate less than 1 inch/yr and a bone age >14 yr in girls and >16 yr in boys

Concurrent treatment with GH and a gonadotropin-releasing hormone (GnRH) agonist has been used in the hope that interruption of puberty will delay epiphyseal fusion and prolong growth.
Recombinant IGF-1 is approved for use in the United States. It is given subcutaneously twice a day. The risk of hypoglycemia is reduced by giving the injections concurrently with a meal or snack. These conditions include abnormalities of the GH receptor, as well as severe GH deficiency in patients who have developed antibodies to administered GH.

GH is currently approved in the United States for treating children with growth failure as a result of Turner syndrome, end-stage renal failure before kidney transplantation, Prader-Willi syndrome, intrauterine growth retardation, and idiopathic short stature.

Adverse effect
1-Some patients treated with GH have developed leukemia
2-pseudotumor cerebri, slipped capital femoral epiphysis, gynecomastia, and worsening of scoliosis.
3-Fasting and postprandial insulin levels are characteristically low before treatment, and they normalize during GH replacement. Treatment does not increase risk of type 1 diabetes, but it may increase the risk of type 2 diabetes.
4-Use of recombinant GH over the past 2 decades has eliminated the risk for CK(Creutzfeldt-Jakob ) disease and reduced the risk of antibody formation during treatment.